High-pressure combustion technology is increasingly used for power generation. As with all combustion-based power generation, emissions are a primary concern. Some commercially available systems are based on a combustor that burns a gaseous, liquid, or solid fuel using gaseous oxygen at near-stoichiometric conditions in the presence of recycled water. The products of this combustion are primarily a high temperature, high pressure mixture of steam and CO2. Fuels that are suitable for combustion in such a system include natural gas, syngas from coal, refinery residues, landfill gas, bio-digester gases, coal, liquid hydrocarbons, and renewable fuels such as glycerin from bio-diesel production facilities.
The hot, high pressure output of a combustor can be used to drive conventional or advanced steam turbines or modified aero-derivative gas turbines that operate at high temperatures and intermediate pressures. Downstream of the turbines, the exhaust gases can be separated and the separated CO2 can be sequestered or stored so as to avoid venting greenhouse gases. Systems such as this are available from Clean Energy Systems of Rancho Cordova, Calif.
Despite advances in combustion and turbine technologies, it remains desirable to further increase the efficiency of combustion-based power generation systems.